VHF Transmitting but not Receiving

emsworthy

emsworthy

Well-Known Member
Joined
15 Jul 2009
Messages
875
Location
Emsworth'ish
Visit site
Hi all,

I'm a bit baffled by a problem I'm having since installing a deck plug/socket for our VHF aerial connection last week. On doing a radio check to Solent Coastguard (mid-week on ch.67 before anyone comments! :p) I got no reply, so I switched on my handheld and called up again and heard the "...receiving you loud and clear..." response from Solent CG on the HH but not the fixed set.

I was always of the belief that if there was an aerial problem it would manifest in poor transmission first especially on low power so this has totally confused me. Can anyone shed any light on the matter? I am pretty certain all of the connections to the plug and socket were well made.

It's one of these.
 
try emergency antenna plugged into the back of the set
that eliminates the set.

anyway - you're more likely to notice an antenna problem through poor reception as that is when the setup has to be more sensitive ...
 
Had exactly this problem a couple of weeks ago after wiring up a new antenna. The set was pretty new to us and in the fussing about it had pressed its own buttons and jumped to Canadian frequencies. Worked fine on CH16 with the Coastguard but we couldn't hear the replies from the marina on CH80.

I'm sure you've checked this already but gremlins of this sort are quite frequent pests....
 
emsworthy said:
Hi all,

I'm a bit baffled by a problem I'm having since installing a deck plug/socket for our VHF aerial connection last week. On doing a radio check to Solent Coastguard (mid-week on ch.67 before anyone comments! :p) I got no reply, so I switched on my handheld and called up again and heard the "...receiving you loud and clear..." response from Solent CG on the HH but not the fixed set.

I was always of the belief that if there was an aerial problem it would manifest in poor transmission first especially on low power so this has totally confused me. Can anyone shed any light on the matter? I am pretty certain all of the connections to the plug and socket were well made.

It's one of these.
Click to expand...

Can you clarify: You had no response on the fixed set which is connected to the aerial via the new connector. You did get response on the hand held. Why would this indicate a receive but not a transmission fault on the fixed set? Was the HH connected to the aerial?
Or am I missing something?
 
What current does the fixed transceiver take during transmit?

Can you hear the fixed transceiver on the hand-held when you transmit?

If listening on Channel 11, do you hear QHM or try Channel 12 and listen for VTS Southampton.

If the emergency antenna fails to produce a result PM me I am in Portsmouth.
 
Salty John said:
Can you clarify: You had no response on the fixed set which is connected to the aerial via the new connector. You did get response on the hand held. Why would this indicate a receive but not a transmission fault on the fixed set? Was the HH connected to the aerial?
Or am I missing something?
Click to expand...

I think you will find that he called on the fixed set and heard the response from the CG on the HH but not on the fixed set.
 
Salty John said:
Thanks,Vic, got it now.
Click to expand...

Vic beat me to it! Yes, Txd on the fixed and only Rxd on the HH.

I have also adjusted the squelch and volume to eliminate that.

To add a little more detail, with a mate calling the fixed set on the HH away from the boat about 50 meters it receives fine so it is clearly a range issue more than a complete failure to receive.
 
emsworthy said:
To add a little more detail, with a mate calling the fixed set on the HH away from the boat about 50 meters it receives fine so it is clearly a range issue more than a complete failure to receive.
Click to expand...
Sounds so much like the issue we had with our boat when we first got her - coming out of Chi we couldn't hear the Portsmouth traffic - yet the hh could ... we replaced the masthead antenna and cable - all fine there after ....
 
It could really just mean your antenna is poor and HMCG has a better receiver than you.

It could be that you have some corrosion which gives a semiconductor effect in the connector, your transmit power is enough to get over the 'diode voltage drop' while the receive power is very much smaller.
Check everything is clean and well connected, including earth braids on coax etc.
 
Gorf said:
Can you hear anything at all on any channel?
Click to expand...

No, other than from my own handheld when it's within shouting distance. I had the fixed set switched on and monitoring ch16 all day Saturday and Sunday and for a bank holiday weekend it was spookily silent, so I can only presume not!
 
lw395 said:
It could really just mean your antenna is poor and HMCG has a better receiver than you.

It could be that you have some corrosion which gives a semiconductor effect in the connector, your transmit power is enough to get over the 'diode voltage drop' while the receive power is very much smaller.
Check everything is clean and well connected, including earth braids on coax etc.
Click to expand...

I'm beginning to fear you could be right. :( The mast has only just gone back up so I really don't fancy to idea of replacing the entire antenna and cable run. I think I'll try re-making the connections first ensuring they are squeaky clean.

Thanks to all for the replies.
 
The cable plug at the bottom of the run is usually the worst, so hopefully a trim of the cable and a new connection will sort it.
 
KellysEye said:
No need to call the coastguard just call the handheld.
Click to expand...

Or from where he is - just call Chi Marina or Chichester Harbour Launch - but only if it's quiet!!

You could always scan a few channels on the HH, find an active one then see if you're getting more on the main set - CH16 is normally fairly busy anyway - but you could always see if you can receive either Soton VTS or Portsmouth QHM without needing to transmit.
 
You must log in or register to reply here.

Share this page

Top